This invention generally pertains to a polymer useful for imparting good conditioning properties to skin. The polymer comprises an ethylenically unsaturated addition polymerizable monomer containing an alkoxylated nitrogen salt of sulfonic acid. The polymers may also include neutral, anionic, and/or cationic monomers. Skin conditioning products generally are considered to function to improve such properties as retention of skin moisture, softening of skin, attraction of air moisture, retardation of skin water loss, feel and reduction of skin irritations caused by contact with detergents, soaps and the like. Historically, two broad areas of skin care products could be considered as skin conditioners: Emollients and Humectants. Emollients function to provide improved moisture retention in the skin and plasticization/softening of the skin. Common commercial emollients are mineral oil; petrolatum; aliphatic alcohols, such as stearyl alcohol; lanolin and its derivatives; glycol stearate; and fatty acids, such as triethanolamine oleate. Humectants function to attract moisture, retard evaporation of H.sub.2 O from the skin surface, and plasticize/soften skin. Common commercial humectants are glycerin, propylene glycol, sorbitols, and polyethylene glycols.
A desirable skin conditioner should impart all or some of the attributes of an emollient and a humectant, as well as provide an improved feel to the skin after treatment and/or reduce skin irritation caused by other components in the conditioner such as soaps, detergents, foam boosters, surfactants, perfumes and the like. Recently, cationic polymers have been used as skin conditioners. The two most often used are Merquat 550 from Merck-poly(acrylamode-(co)diallyl dimethyl ammonium chloride) and Polymer JR from Union Carbide--a quaternary nitrogen-containing hydroxyethyl cellulose.
One patented product is similar to the compound(s) of interest here, but not equivalent in chemical structure or skin conditioning properties. U.S. Pat. Nos. 4,065,422 and 4,128,631 are directed to personal care products which serve to impart a feeling of lubricity on keratinous surfaces. These homopolymer products contain high molecular weight polymeric salts of 2-acrylamido-2-methylpropane sulfonic acid (AMPS). Such AMPS homopolymers have a molecular weight ranging from 1 to 5 million.
The polymer of the invention is believed to constitute a very significant improvement in the skin conditioning art because such polymer, when contrasted to the products mentioned above, exhibits a superior combination of skin care properties. These properties include improved moisture retention, and improved feel of the skin during and after treatment.